program ex;
type
 ss=array[1..1000,1..1000]of real;
 data=record
  x,y:longint;
 end;
 sz=array[1..1000]of data;
var
 map:ss;
 f:sz;
 n,m:integer;
procedure init;
 var
  i,j,a,b:integer;
 begin
  assign(input,'roads.in');
  assign(output,'roads.out');
  reset(input);
  rewrite(output);
  readln(n,m);
  for i:=1 to n do readln(f[i].x,f[i].y);
  for i:=1 to n-1 do
   for j:=i+1 to n do
    begin
     map[i,j]:=sqrt(sqr(f[i].x-f[j].x)+sqr(f[i].y-f[j].y));
     map[j,i]:=map[i,j];
    end;
  for i:=1 to n do map[i,i]:=0;
  for i:=1 to m do
   begin
    readln(a,b);
    map[a,b]:=0;
    map[b,a]:=0;
   end;
 end;
procedure main;
 var
  i,j,k,k1,k2:integer;
  tail:integer;
  flag:array[1..1000]of boolean;
  que:array[0..1000]of integer;
  min,sum:real;
 begin
  fillchar(flag,sizeof(flag),true);
  fillchar(que,sizeof(que),0);
  flag[1]:=false;
  que[0]:=1;que[1]:=1;
  sum:=0;
  for i:=1 to n-1 do
   begin
    min:=99999999;
    for j:=1 to que[0] do
     for k:=1 to n do
      if flag[k] then
       if map[que[j],k]<min then
        begin
         min:=map[que[j],k];
         k1:=k;
        end;
    sum:=sum+min;
    inc(que[0]);
    que[que[0]]:=k1;
    flag[k1]:=false;
   end;
  writeln(sum:0:2);
  close(output);
 end;
begin
 init;
 main;
end.